Method for detecting metal residues in etching reaction cavity

Abstract

The invention provides a method for detecting metal residues in an etching reaction cavity. The method comprises the steps that S01, a wafer is conveyed into the etching reaction cavity of etching equipment; s02, starting a spectrograph in the etching equipment; s03, detecting the spectral line of at least one specific wavelength band in the etching reaction cavity by using a spectrograph at a first set time, and obtaining a reference value of the intensity of the spectral line of the specific wavelength band; s04, at a second set time, using the spectrometer to etch the spectral line of at least one specific wavelength band in the reaction cavity to detect, and obtaining a test value of the spectral line intensity of the specific wavelength band; and S05, comparing the reference value and the test value of the spectral line intensity of the specific wavelength section, and judging the residual condition of the preset metal in the etching reaction cavity according to a comparison result. According to the method, the optical emission spectrometry is used for detecting the preset metal residue condition in the etching reaction cavity in real time, and the detection result can be used as a basis for judging whether the preset metal residue exists in the etching reaction cavity or not.

Description

Technical Field

[0001] The invention relates to the technical field of semiconductor manufacturing, and in particular to a method for detecting metal residues in an etching reaction chamber. Background Art

[0002] In the existing dual Damascus etching process, because the gas pipeline of the etching equipment contains nickel (Ni) metal components in some gas filter components, and the nickel (Ni) metal easily reacts chemically with the CO (carbon monoxide) gas in the gas pipeline to generate tetracarbon-based nickel (Ni(CO)4) aluminum compounds. This type of aluminum compound is easily transported to the etching reaction chamber with the conveying gas and deposited on the surface of the photoresist, causing the photoresist to not be completely removed during the stripping process and remain on the wafer surface, resulting in abnormalities in subsequent etching process steps. Therefore, it is particularly important to monitor whether there is nickel (Ni) metal residue in the etching reaction chamber.

[0003] In the prior art, the method for measuring the metal residue in the etching reaction chamber is usually to use XPS or ICPMS to detect the metal residue composition and content on the surface of one or more etched control samples in an offline state. This type of detection method is time-consuming and cumbersome, and cannot achieve real-time detection of the metal residue in the etching reaction chamber. Summary of the invention

[0004] In order to solve the technical problem of real-time detection of metal residues in an etching reaction chamber, the present invention provides a method for detecting metal residues in an etching reaction chamber. The method uses optical emission spectroscopy (OES), also known as spectrometer, to perform real-time detection of preset metal residues in the etching reaction chamber. The detection result can be used as a basis for judging whether there are preset metal residues in the etching reaction chamber.

[0005] To achieve the above object, the present invention provides a method for detecting metal residues in an etching reaction chamber, comprising:

[0006] S01: transferring the wafer to an etching reaction chamber of an etching device;

[0007] S02: Turn on the spectrometer in the etching device;

[0008] S03: At a first set time, using the spectrometer to detect spectral lines of at least one specific wavelength band in the etching reaction chamber to obtain a reference value of the spectral line intensity of the specific wavelength band; the specific wavelength band is a wavelength band corresponding to a preset metal in the plasma in the etching reaction chamber;

[0009] S04: at a second set time, using the spectrometer to detect at least one spectral line of the specific wavelength band in the etching reaction chamber to obtain a test value of the spectral line intensity of the specific wavelength band;

[0010] S05: Compare the reference value and the test value of the spectral line intensity in the specific wavelength band, and determine the residual condition of the preset metal in the etching reaction chamber according to the comparison result.

[0011] Optionally, in step S05, the step of comparing the reference value and the test value of the spectral line intensity of the specific wavelength band, and judging the residual condition of the preset metal in the etching reaction chamber according to the comparison result includes:

[0012] Obtaining a spectral line intensity ratio of the specific wavelength band, wherein the spectral line intensity ratio is set to be a ratio of a test value of the spectral line intensity to a reference value;

[0013] If the spectral line intensity ratio is less than or equal to a preset value of the spectral line intensity ratio, it is determined that the residual amount of the preset metal in the etching reaction chamber is within a normal range;

[0014] If the spectral line intensity ratio is greater than a preset value of the spectral line intensity ratio, it is determined that the residual amount of the preset metal in the etching reaction chamber exceeds a normal range.

[0015] Optionally, the preset metal has a plurality of the specific wavelength bands;

[0016] Step S03 also includes: obtaining the reference value of the spectral line intensity of each specific wavelength band respectively through the spectrometer;

[0017] Step S04 also includes: obtaining test values ​​of the spectral line intensity of each specific wavelength band respectively through the spectrometer.

[0018] Optionally, step S05 further includes: comparing the spectral line intensity ratio of each of the specific wavelength bands with the preset value, and recording the number of the specific wavelength bands whose spectral line intensity ratio is greater than the preset value;

[0019] If the number of the specific wavelength bands is less than or equal to the target number, it is determined that the residual amount of the preset metal in the etching reaction chamber is within a normal range;

[0020] If the number of the specific wavelength bands is greater than the target number, it is determined that the residual amount of the preset metal in the etching reaction chamber exceeds a normal range.

[0021] Optionally, the preset metal is nickel element.

[0022] Optionally, the preset value of the spectral line intensity ratio is set to 1.2.

[0023] Optionally, the number of the specific wavelength bands of the nickel element is 6, and the target number is set to 3.

[0024] Optionally, the first set time is set within a range where the working time of the RF component in the spectrometer is less than or equal to 2 hours, and / or the second set time is set within a range where the working time of the RF component in the spectrometer is greater than 2 hours.

[0025] Optionally, the method for detecting metal residues in the etching reaction chamber further includes:

[0026] The detection period of the residual amount of the preset metal in the etching reaction chamber is 24h to 120h.

[0027] Optionally, the spectrometer is connected to a display screen;

[0028] Step S05 also includes: displaying a curve graph of the spectral line intensity ratios in different wavelength bands on the display screen.

[0029] The present application provides a method for detecting metal residues in an etching reaction chamber, which uses optical emission spectroscopy (OES) to perform real-time detection of a preset metal residue in the etching reaction chamber to achieve the purpose of real-time monitoring. The spectroscopy method can use the intensity of spectral lines of different wavelengths generated by each element during the dissociation process of the plasma in the etching reaction chamber to detect the residual change of each element in the etching reaction chamber, and then obtain the residual amount of the preset metal in the etching reaction chamber. The detection result can be used as a basis for judging whether the preset metal residue in the etching reaction chamber is present, and the operation is convenient and the accuracy is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a flow chart of a method for detecting metal residues in an etching reaction chamber in a preferred embodiment of the present invention;

[0031] Figure 2 A simplified structural diagram of an etching reaction chamber and a spectrometer in an etching device in a preferred embodiment of the present invention;

[0032] Figure 3 It is a curve diagram of the spectral line intensity ratio at different wavelength bands in a preferred embodiment of the present invention, wherein the arrow position represents the spectral line intensity ratio of the nickel element at different specific wavelength bands, and the straight line parallel to the abscissa represents the preset value of the spectral line intensity ratio;

[0033] Figure 4 It is a structural block diagram of an etching device in a preferred embodiment of the present invention.

[0034] The reference numerals are described as follows:

[0035] Etching reaction chamber 1; spectrometer 2; plasma 3; display screen 4. DETAILED DESCRIPTION

[0036] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. The advantages and features of the present invention will become more apparent from the following description. It should be noted that the accompanying drawings are in very simplified form and in non-precise proportions, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention.

[0037] The orientation or position relationship indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like are based on the orientation or position relationship shown in the drawings and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred mechanism or element must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting the present invention.

[0038] In the present invention, unless otherwise clearly specified and limited, the terms "installation", "connection", "fixation" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or a connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] Furthermore, those skilled in the art may combine and associate different embodiments or examples and features of different embodiments or examples described in this specification without mutual contradiction.

[0040] Reference Figure 1 and Figure 2 As shown, a preferred embodiment of the present application provides a method for detecting metal residues in an etching reaction chamber, comprising:

[0041] S01: Transfer the wafer to the etching reaction chamber 1 of the etching equipment.

[0042] S02: Turn on the spectrometer 2 in the etching equipment.

[0043] S03: At the first set time T1, the spectrometer 2 is used to detect the spectral line of at least one specific wavelength band in the etching reaction chamber 1 to obtain the reference value I1 of the spectral line intensity of the specific wavelength band. The specific wavelength band is the wavelength band corresponding to the preset metal in the plasma 3 in the etching reaction chamber 1.

[0044] S04: At the second set time T2, the spectrometer 2 is used to detect the spectral line of at least one specific wavelength band in the etching reaction chamber 1 to obtain a test value I2 of the spectral line intensity of the specific wavelength band.

[0045] S05: Compare the reference value I1 and the test value I2 of the spectral line intensity of the specific wavelength band, and determine the residual condition of the preset metal in the etching reaction chamber 1 according to the comparison result.

[0046] The present invention provides a method for detecting metal residue in an etching reaction chamber, which uses optical emission spectroscopy (OES) to perform real-time detection of a preset metal residue in an etching reaction chamber 1, so as to achieve the purpose of real-time monitoring. The spectroscopy method can use the intensity of spectral lines of different wavelengths generated by each element during the dissociation process of the plasma 3 in the etching reaction chamber 1 to detect the residual change of each element in the etching reaction chamber 1, and then know the residual amount of the preset metal in the etching reaction chamber 1. The detection result of the spectrometer 2 can be used as a basis for judging whether the preset metal residue in the etching reaction chamber 1 exists, and the operation is convenient and the accuracy is high.

[0047] It should be noted that the spectrometer 2 (including but not limited to a radio frequency glow discharge spectrometer) can cause atoms or molecules in the plasma 3 to be excited to an excited state by electrons, and in the process of returning from the excited state to a low energy level, the atoms or molecules will emit a spectral line of a specific wavelength (i.e., a characteristic spectral line of the element). The spectral line of a specific wavelength can enter the spectrometer 2, and the spectrometer 2 can obtain the spectral line intensity of a specific wavelength band of a preset metal.

[0048] Furthermore, the spectral line intensity of the specific wavelength band obtained by the spectrometer 2 is proportional to the residual amount of the preset metal in the etching reaction chamber 1, that is, the more the residual amount of the preset metal in the etching reaction chamber 1, the higher the spectral line intensity of the specific wavelength band of the preset metal obtained by the spectrometer 2.

[0049] Since the wavelengths of the spectral lines excited by different types of metals are different, the spectrometer 2 can be used to detect the changes in the intensity of the spectral lines generated by the preset metal during the dissociation process of the plasma 3 in the etching reaction chamber 1, thereby knowing the changes in the residual concentration of the preset metal in the etching reaction chamber 1, and then judging the residual situation of the preset metal in the etching reaction chamber 1.

[0050] Specifically, if the spectral line intensity of a specific wavelength band of a preset metal increases significantly under a set process node of wafer etching, it means that the residual amount of the preset metal in the etching reaction chamber 1 increases significantly under this process node. At this time, the operator needs to take necessary measures to remove the excess preset metal residue in the etching reaction chamber 1.

[0051] As a preferred embodiment, in step S05, the reference value I1 and the test value I2 of the spectral line intensity of a specific wavelength band are compared, and the step of judging the residual condition of the preset metal in the etching reaction chamber 1 according to the comparison result includes:

[0052] The spectral line intensity ratio of a specific wavelength band is obtained, and the spectral line intensity ratio is set as the ratio of the test value I2 of the spectral line intensity to the reference value I1.

[0053] If the spectral line intensity ratio (i.e., I2 / I1) is less than or equal to the preset value I0 (set value) of the spectral line intensity ratio, i.e., I2 / I1≤I0, it is determined that the residual amount of the preset metal in the etching reaction chamber 1 is within the normal range, that is, at the second set time T2, the residual amount of the preset metal in the etching reaction chamber 1 has not increased significantly.

[0054] If the spectral line intensity ratio (i.e., I2 / I1) is greater than the preset value I0 of the spectral line intensity ratio, i.e., I2 / I1>I0, it is determined that the residual amount of the preset metal in the etching reaction chamber 1 exceeds the normal range, that is, at the second set time T2, the residual amount of the preset metal in the etching reaction chamber 1 increases significantly. At this time, the etching reaction chamber 1 is suspected to be contaminated by the preset metal, and the operator is required to remove the excess preset metal residue in the etching reaction chamber 1 to prevent the preset metal and its compounds from being deposited on the photoresist surface and affecting the subsequent process of the wafer.

[0055] It should be noted that the preset value I0 of the spectral line intensity ratio can be set based on experience.

[0056] It should be known that the comparison method of the reference value I1 and the test value I2 of the spectral line intensity is not limited to obtaining the ratio of the test value I2 to the reference value I1 and comparing the ratio with the preset value I0. In other embodiments, the difference between the test value I2 and the reference value I1 of the spectral line intensity can also be obtained, and the difference between the test value I2 and the reference value I1 can be compared with the preset value I0 to determine the preset metal residue in the etching reaction chamber 1.

[0057] In a specific example, the preset metal is nickel. If the spectrometer 2 detects that the residual amount of nickel in the etching reaction chamber 1 increases, the excess nickel in the etching reaction chamber 1 may react with carbon monoxide (CO) gas to generate a tetracarbon-based nickel (Ni(CO)4) aluminum compound, which is easily deposited on the surface of the photoresist, resulting in incomplete residual photoresist during wafer stripping, causing abnormalities in subsequent etching process steps of the wafer.

[0058] It should be understood that the preset metal may also be set to other metals besides metallic nickel, that is, the above detection method may also be applicable to detecting the residual conditions of other preset metals besides metallic nickel in the etching reaction chamber 1 .

[0059] The present invention can perform real-time detection of the residual nickel element in the etching reaction chamber 1 through the spectrometer 2. When it is detected that the residual nickel element in the etching reaction chamber 1 increases significantly, a prompt message can be issued to remind the operator to clean the preset metal residue in the etching reaction chamber 1 in time.

[0060] Exemplarily, when the preset metal is nickel element, the preset value I0 of the spectral line intensity ratio may be set to 1.2.

[0061] With such configuration, when the spectral line intensity ratio of a specific wavelength band detected by the spectrometer 2 is less than or equal to 1.2, it can be determined that the residual amount of the preset metal in the etching reaction chamber 1 is within the normal range; when the spectral line intensity ratio of a specific wavelength band detected by the spectrometer 2 is greater than 1.2, it can be determined that the residual amount of the preset metal in the etching reaction chamber 1 exceeds the normal range.

[0062] In a preferred case, the preset metal has a plurality of specific wavelength bands, that is, the preset metal generally has a corresponding plurality of wavelength bands.

[0063] Furthermore, step S03 also includes: obtaining the reference value I1 of the spectral line intensity of each specific wavelength band respectively through the spectrometer 2.

[0064] Step S04 also includes: obtaining the test value I2 of the spectral line intensity of each specific wavelength band respectively through the spectrometer 2.

[0065] Furthermore, step S05 also includes: comparing the spectral line intensity ratio of each specific wavelength band (i.e., the ratio of the test value I2 of the spectral line intensity to the reference value I1) with the preset value I0, and recording the number N1 of specific wavelength bands whose spectral line intensity ratio is greater than the preset value I0 (i.e., I2 / I1>I0).

[0066] If the number N1 of specific wavelength bands is less than or equal to the target number N0, that is, N1≤N0, it is determined that the residual amount of the preset metal in the etching reaction chamber 1 is within the normal range, that is, within the second set time T2, the residual amount of the preset metal in the etching reaction chamber 1 has not increased significantly.

[0067] If the number N1 of specific wavelength bands is greater than the target number N0, that is, N1>N0, it is determined that the residual amount of the preset metal in the etching reaction chamber 1 exceeds the normal range, that is, within the second set time T2, the residual amount of the preset metal in the etching reaction chamber 1 increases significantly, and at this time, the etching reaction chamber 1 is suspected to be contaminated by the preset metal.

[0068] It should be explained that since the preset metal usually has multiple specific wavelength bands, the baseline value I1 and test value I2 of each specific wavelength band can be obtained respectively through the above-mentioned detection method, and the spectral line intensity ratio of each specific wavelength band (ie I2 / I1) can be compared with the preset value I0.

[0069] In addition, the target number N0 of specific wavelength bands can be set based on experience. If the number of specific wavelength bands whose spectral line intensity ratio is greater than the preset value I0 among all specific wavelength bands is greater than the target number N0, it means that the risk of the preset metal residue in the etching reaction chamber 1 exceeding the normal range increases, and it can be determined that the etching reaction chamber 1 is suspected of being contaminated by the preset metal.

[0070] Furthermore, the first set time T1 is preferably set within the range where the working time (i.e., RF hours) of the radio frequency component (not shown) in the spectrometer 2 is less than or equal to 2 hours, i.e., RF hours ≤ 2 hours. At this time, the residual amount of the preset metal in the etching reaction chamber 1 is low, which can be used as the reference value I1 of the spectral line intensity of a specific wavelength band.

[0071] Furthermore, the second set time T2 is preferably set within the range where the working time (i.e., RF hours) of the RF component in the spectrometer 2 is greater than 2 hours, i.e., RF hours>2 hours. At this time, the etching process of the wafer in the etching reaction chamber 1 is basically stable, so the accuracy of the detection result of the spectrometer 2 can be improved.

[0072] Figure 3 The figure is a curve diagram of the spectral line intensity ratio at different wavelength bands in a preferred embodiment of the present invention. The horizontal axis represents the wavelength of the spectral line detected by the spectrometer 2, and the vertical axis represents the spectral line intensity ratio of each wavelength band detected by the spectrometer 2, and the spectral line intensity ratio is the ratio of the test value I2 of the spectral line intensity to the reference value I1. The straight line parallel to the horizontal axis represents the preset value I0 of the spectral line intensity ratio, and the arrow position represents the spectral line intensity ratio of the nickel element at different specific wavelength bands.

[0073] Generally speaking, when performing the detection of metal residues in the etching reaction chamber 1 , it is necessary to detect multiple groups of wafers separately. Figure 3 Each spectral line intensity ratio curve in the figure represents the detection result of a corresponding group of wafers in the etching reaction chamber 1. Among them, the black spectral line intensity ratio curve represents the spectral line intensity ratio of all specific wavelength bands detected by the spectrometer 2 when the RF time does not exceed 2h. The red spectral line intensity ratio curve in the figure represents the spectral line intensity ratio of all specific wavelength bands detected by the spectrometer 2 when the RF time exceeds 2h.

[0074] See also Figure 3In an illustrative example, the nickel element has six specific wavelength bands, and the wavelengths of the six specific wavelength bands are 231.5 nm, 300.5 nm, 323.5 nm, 341.5 nm, 346.5 nm, and 352.0 nm, respectively.

[0075] Furthermore, the target number N0 of the specific wavelength band of nickel element is set to 3, and the preset value I0 of the spectral line intensity ratio is set to 1.2. Figure 3 As shown, taking the top spectral line intensity ratio curve as an example, the spectral line intensity ratios of the 6 specific wavelength bands of the nickel element are all greater than 1.2. At this time, the number of specific wavelength bands with spectral line intensity ratios greater than 1.2 is greater than 3, indicating that the residual amount of nickel element in the etching reaction chamber 1 corresponding to the top spectral line intensity ratio curve exceeds the normal range.

[0076] Furthermore, the method for detecting metal residues in the etching reaction chamber also includes: the detection period of the preset metal residue amount in the etching reaction chamber 1 is 24h to 120h, that is, the detection of the metal residues in the etching reaction chamber 1 can be repeated within a time period of 24h to 120h, thereby realizing real-time detection and monitoring of the preset metal residues in the etching reaction chamber 1.

[0077] It should be noted that, in addition to real-time monitoring of the preset metal residue in the etching reaction chamber 1 at the etching process node, the spectrometer 2 can also be applied to conventional wafer detection (such as wafer etching endpoint detection), which will not be elaborated here.

[0078] Reference Figure 4 As shown, the spectrometer 2 is connected to the display screen 4. Step S05 also includes: displaying a curve graph of the spectral line intensity ratios in different wavelength bands on the display screen 4, that is, displaying the detection result of the spectrometer 2 on the display screen 4, so as to prompt the operator.

[0079] In summary, the present invention provides a method for detecting metal residues in an etching reaction chamber, which uses optical emission spectroscopy (OES) to perform real-time detection of a preset metal residue in an etching reaction chamber 1 to achieve the purpose of real-time monitoring. The spectroscopy method can use the intensity of spectral lines of different wavelengths generated by each element during the dissociation process of the plasma 3 in the etching reaction chamber 1 to detect the residual change of each element in the etching reaction chamber 1, and then obtain the residual amount of the preset metal in the etching reaction chamber 1. The detection result can be used as a basis for judging whether the preset metal residue in the etching reaction chamber 1 is present, and the operation is convenient and the accuracy is high.

[0080] The above description is only a description of the preferred embodiments of the present invention, and is not intended to limit the scope of the present invention. Any changes or modifications made by a person skilled in the art in the field of the present invention based on the above disclosure shall fall within the protection scope of the present invention.

Claims

1. A method for detecting metal residue in an etching reaction chamber, characterized in that: include: S01: transferring the wafer to an etching reaction chamber of an etching device; S02: Turn on the spectrometer in the etching device; S03: At a first set time, using the spectrometer to detect spectral lines of at least one specific wavelength band in the etching reaction chamber to obtain a reference value of the spectral line intensity of the specific wavelength band; the specific wavelength band is a wavelength band corresponding to a preset metal in the plasma in the etching reaction chamber; S04: at a second set time, using the spectrometer in the etching reaction chamber to detect at least one spectral line of the specific wavelength band to obtain a test value of the spectral line intensity of the specific wavelength band; S05: Compare the reference value and the test value of the spectral line intensity in the specific wavelength band, and determine the residual condition of the preset metal in the etching reaction chamber according to the comparison result.

2. The method for detecting metal residue in an etching reaction chamber according to claim 1, characterized in that: In step S05, the step of comparing the reference value and the test value of the spectral line intensity of the specific wavelength band, and judging the residual condition of the preset metal in the etching reaction chamber according to the comparison result includes: Obtaining a spectral line intensity ratio of the specific wavelength band, wherein the spectral line intensity ratio is set to be a ratio of a test value of the spectral line intensity to a reference value; If the spectral line intensity ratio is less than or equal to a preset value of the spectral line intensity ratio, it is determined that the residual amount of the preset metal in the etching reaction chamber is within a normal range; If the spectral line intensity ratio is greater than a preset value of the spectral line intensity ratio, it is determined that the residual amount of the preset metal in the etching reaction chamber exceeds a normal range.

3. The method for detecting metal residue in an etching reaction chamber according to claim 2, characterized in that: The preset metal has a plurality of the specific wavelength bands; Step S03 also includes: obtaining the reference value of the spectral line intensity of each specific wavelength band respectively through the spectrometer; Step S04 also includes: obtaining test values ​​of the spectral line intensity of each of the specific wavelength bands respectively through the spectrometer.

4. The method for detecting metal residue in an etching reaction chamber according to claim 3, characterized in that: Step S05 further includes: comparing the spectral line intensity ratio of each of the specific wavelength bands with the preset value, and recording the number of the specific wavelength bands whose spectral line intensity ratio is greater than the preset value; If the number of the specific wavelength bands is less than or equal to the target number, it is determined that the residual amount of the preset metal in the etching reaction chamber is within a normal range; If the number of the specific wavelength bands is greater than the target number, it is determined that the residual amount of the preset metal in the etching reaction chamber exceeds a normal range.

5. The method for detecting metal residue in an etching reaction chamber according to claim 4, characterized in that: The preset metal is nickel element.

6. The method for detecting metal residue in an etching reaction chamber according to claim 5, characterized in that: The preset value of the spectral line intensity ratio is set to 1.

2.

7. The method for detecting metal residue in an etching reaction chamber according to claim 5, characterized in that: The number of the specific wavelength bands of the nickel element is 6, and the target number is set to 3.

8. The method for detecting metal residue in an etching reaction chamber according to any one of claims 1 to 7, characterized in that: The first set time is set within a range where the working time of the radio frequency component in the spectrometer is less than or equal to 2 hours, and / or the second set time is set within a range where the working time of the radio frequency component in the spectrometer is greater than 2 hours.

9. The method for detecting metal residue in an etching reaction chamber according to any one of claims 1 to 7, characterized in that: Also includes: The detection period of the preset metal residue in the etching reaction chamber is 24h to 120h.

10. The method for detecting metal residue in an etching reaction chamber according to any one of claims 2 to 7, characterized in that: The spectrometer is connected to the display screen; Step S05 also includes: displaying a curve graph of the spectral line intensity ratios in different wavelength bands on the display screen.

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